Punching bag



FIG. 1 is a perspective view of the punching bag showing my design;

FIG. 2 is a left side view thereof; and

FIG. 3 is a right side view thereof; and

FIG. 4 is a top plan view thereof; and

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear side view thereof. 

The ornamental design for a punching bag, as shown and described. 